Alternating-current regulator.



R. s. MOLEODL ALTERNATING CURRENT REGULATOR.

APPLICATION FILED 00w. 22,1906.

Inc/62m) Patented Mar. 2, 1909.

6 SHEETs-sHEBT 1.

YR. s. MoLEOD.

ALTERNATING CURRENT REGULATOR. APPLICATION rILnn our. 22, nos.

5 SHEETS-#HBET 2.

Patented Mar. 2, 1909.

R. S. MoLEOD. ALTERNATIN G CURRENT REGULATOR. APPLICATION FILED our. 22,1906.

Patented Mar. 2, 1909.

6 SHEETS-SHEET 4.

V RHEOSTA T RS N wrr u R. S. MOLEOD.

ALTERNATIN G CURRENT REGULATOR. APPLICATION FILED 00w. 22,1906.

Patented Mar. 2, 1909.

5 SHEETS-SHEET 6.

. may: J. M52204? U ITED STATES gran onrrcn ALTEBNATING-CUBRENT REGULATOR. I

i No. 913,757.

Specification of Letters Patent. Applicationflled October 22, 1906. Serial No. 840,060.

Patented March 2, 1909.

all :whom 'it may concern: Be 1t known that I, ROBERT STAFFORD MoLEoo, a subject of the King of Great I Britain, and a resident of Didsbury, Manchester, England, have invented certain new and useful Improvements in Alternating- Current Regulators, of which the following is a specification.

This invention relates to apparatus for controlling the supply of energy from alternating current generators or mains to alternating current motors, and is especially applicable toalternating current winding apparatus and the like, in which the motor isusually of considerable size, and in which the energy taken from the generator is very considerable at starting, and the object of 1 the invention is to provide auxiliary altererator or mains-is maintained fairlycon- I stant, and economy of ,working insured by reducing the peak of the load on the gennating cur-rent plant so arranged and connected tothe generator, or mains, the motor, anda fly-wheel that energy is accumulated at those periods when the energy demanded by the motor is small, and is supplied to the motor when it-s demand, say at starting, is great; in this way the demand on the generator. I V

Broadly described such apparatus, con structed in accordance with my invention, comprises ;-an' alternating current main motor A electrically connected to, the gen- ;erator or-supply mains B; -an'auxiliary alternating current -ma chine C, electrically connected to the generator or the supply I fmains, and either mechanically connected to rotating mass and thus store up energy in it;

a fly-wheel I) or so built that its rotor forms.

a heavy fly-wheel; and means E, for rotat ing at variable speeds, and preferably in either direction, that partof the auxiliary machine which is usually referred to as the stator, but which, for the sake of clearness, I will hereinafter refento as the case.

Bycontrolling the rotation of the case I am enabled, by rotating it in the same directionas the, motor, to cause the machine to act as a motor and to accelerate the heavy and by reducing the speed of rotation of the case, or reversing its rotation,'to cause the machine to act as a dynamo, which, by. retarding the heavy rotating mass, converts the energy stored therein into electrical en= ergy which it transfers to the mains feeding the main motor. In this way energy 15 stored up in the heavy rotating mass when the load on the main motor is light, which energy'is returned to the mains when the load on the main motor-is heavy.

I have illustrated my invention in the accompanying drawings in which;

Figure 1 represents the arrangement when the auxiliary machine is a three phase induction machine; Fig. 2represent's the arrangement when the auxiliary machine is a three phase synchronous machine; Fig. 1 is a diagrammatic representation showing the relation and connection of the broad features of the invention; Fig. 3 shows the preferred arrangement for starting, and rotating the case of, the auxiliary'machuie which is shown as a synchronous machine; and Figs. 4, 5, 6, 7 and 8 arediagrams to further explain the arrangements illustrated in Fig. 3.

I will in the firstinstance, by way of example,'describe my invention with reference to an alternating current induction motor used as the auxiliary motor, in which case the arrangement which is diagrammatically represented in Fi 1 of the accompanying drawings, is as fo lows:

A is the main motor connected to the supply mains B by a-controlling switch Ac; As is the stator, Ar the rotor, and A0 the cons trolling rotor resistance of this motor.

C is the auxiliary motor connected to the supply mains by a C1" is the rotor, and C0 the controllmg rotor. resistance of this motor. The part of this motor usually termed the stator 1s, accord-V ing to the present invention adapted to rotate, and stated, to avoid ambiguity, that part Cs will be referred to as the case, it is.to be understood however that electrically it is constructed, arranged and wound as a stator; the case is provided with three slip controlling switch Co," I

rings 8. and the current is led to the case or I stator windings through the brushes b.

A 'heavy fly-wheel D is connected to the rotor Or of the auxiliary motor. I so arrange the stator C8 of this machine that it is adapted to be rotated, when the demand for energy by,- the main motor is small, in such direction as to increase the speed of the rotor Cr and attached fly-wheel D, and so store up energy in the latter, which energy is returned to the mains B and supplied to the main motor A when the demand by the latter is increased; the transfer being effected by the reduction of speed or the reversal of rotation of the case or stator Cs of the auxiliary machine C, whereby therelative movement between its case and its rotor exceeds that which corresponds with synchronism and the machine becomes a generator transforming the kinetic ener previously stored u m the fly-wheel into electrical ener w 'ch it delivers to the mains to supp ement that of the main generator.

The means for rotating the case may be either mechanical or electrical; preferably they consist of an electro motor from the mains B. In the arrangement illustrated the case C8 of the motor 0 is adapted to be rotated by a motor E, which in this arrangement is a three phase induction motor; the rotor Er of this motor is connected by suitable gear such as the spur wheels 9 and h to the case. The stator E8 of the motor E is connected to the mains by a reversing switch F, and its rotor currents are controlled by a resistance E0. In some cases I prefer to employ in this arrangement a continuous current motor, as shown in connection with Fig. 3. I

Instead of connecting the motor E to the case C8 by gearing the case may form the rotor of the motor; or in some cases the case Cs may be driven from the main motor A especially when the variation of speed or direction of rotation, or the latter corremotor?,

sponds, (as is the case in a windi with the rate at which it deman s from the mains, sired action of the auxiliary machine.

The energy imparted to the auxiliary rotating system is transferred to it in part through the auxilia machine and in part through the motor E which drives the case of the auxiliary machine, and usually the arrangement would be so make the last mentioned part of the energy relatively as small as poss1ble.

The action is as follows :The auxilia machine C which, as stated, I willin the first instance assume to be a three hase induction machine, is started up eit er with its case stationary or rotated-so as to facilitate the starting,the'resistanoe O0 in the rotor being used to control the rotor currents; if

E energized.

and therefore with the dedesigned as to now the main motor A is either stationary or under light load, the case of the auxiliary machine is maintained in rotation; its rotor with the attached fly-wheel will then run up tosynchronous speed relatively to the rotating case; as soon as the demand for ener by the main motor exceeds, say, the norma the rotation of the case of the auxiliary machine is by control of its .driving motor reduced and if necessary reversed, whereupon the rotor and fly-wheel speed, relatively to the case, exceeds the synchronous speed, and the auxiliary machine acts as a generator, the energy lost by the fly-wheel as it slows down being transferred through the mains to the main motor.

The switches controlling the resistance C0 in the auxiliary machine rotor and the controlling and starting mans F and E0 of the case driving motor are connected together and to the main motor controlling means such as A0 and A0 so that the operations described ma be performed in sequence either by han or automatically.

When the main motor is used to rotate the case and' Where such motor is reversed from time to time, it may be necessary to so connect it to the case that its rotation in one direction is inoperative.

I may, instead of using an induction motor for the auxiliary machine-use a synchronous motorin which case the action is similar except of course that the change in speed or direction of rotation of the case must be made more gradually than when an induction motor 1s used, and that an exciter or rectifier must now be used to excite the field of the synchronous machine. The motor which drives the case would be so arran ed with a resistance that it would to accelerate the case sufliciently rapidly to cause the rotor to pull out of step with the rotating field; its action being to cause enough displacement between the rotor and the field of the auxiliary machine to change the machine from a motor to a generator, or vice versa, as described. 7

I have illustrated in Fig. 2, the modification in which a synchronous motor S is employed instead of the induction motor C. The motor S is shown with a multipolar rotating field S1- connected to the fly wheel D; the armature or case S8 is shown wound for three phase currents and is connected through the switch gear S0 to the mains B;

the current is led to the windings of S8 through the three slip rings s and bushes b. The rotatin field is excited b an exciter K which may e connected to t e shaft of. Sr or be independently drivem The case Se is, as before, geared to the motor E and the not be a le' connections of the motor E and the main motor -A are as described in reference to Fig.

1; the action of the apparatus is also as described.

The motor S being a synchronous motor, it will be necessary to provide suitable means for starting up the rotor Sr and its connected fly-wheel; this may be accomplished in a variety of ways,F or instance, the

motor E may be used to drive the case Ss in a direction opposite to. that in which the stator or case field produced by the three phase currents rotates and at an equal speed; this field then becomes stationary, and the field system Sr can be excited; if now the speed of S8 be gradually reduced and Ss finally brought to rest, the field system 8'! (and the-connected fly-wheel) will follow the rotating field in S8 and rotatefinally relatively to Ss at synchronous speed.

As an alternative the case, rotating motor E may be used to rotate S1" to synchronous speed, a second a'ir'of spur wheels Z and m being provided or this purpose; the pinions may be made to slide, or a clutch may be provided, so.that the pinions may be alternatively engaged with the shaft of the motor E. Or, of'course, an induction motor may be provided for the purpose of starting up the rotor Sr. 1

In some cases the mede of starting 11 synchronous motors in which the field Sr is adapted to be divided in sections and conneqted up as an induction motor rotor, may. be used; in this case S8 may be allowed to run free in the first instance, which eases the starting, and is afterwards gradually brought to rest by means of a brake device.

I have illustrated the preferred'arrangement in Fig; 3.

In this arrangement the main motor A is connected, as described, to

the mains B and the windings of the case R8 of the machine R are connected to the mains B through the slip rings 8 brushes 1') and the switch Re. The rotor R1" of the machineR is connected to a fly-wheel D, and

the three windings of the rotor are connected to resistances R0. The case Rs is rotated by a continuous current motor M, by means of gear wheels, 9 and i The current for the armature Ma of the motor M is obtained from a continuouscurrent machine N, pref erably driven by'being attached to the common shaft ofB. and D T are continuous current mains, and the fields and Nf of M and N are excited from these mains; a

rheostat and reversing. switch V is usedto control the field excitation of N so that its value may be varied froma maximum positive value through zero to a maximum negative value; in this way the current supplied "by N to the armature ofM may be varied in magnitude and direction, and. the direction of rotation and the speed of M v varied ac- V cordingly; the arrangement is also admirably adapted to start-up he arrangement now under consideration I prefer to wind the rotorv -Rr of the machine R'with a three-phase wmding,the

ends a, 3 e, of which are connected through the usfial arrangement of three slip rings and brushes to resistances x 3 and ra of a three part resistance R0; the neutral point w of the winding is also connected through a slip ring to the contact 10 a switch 2 connected to one of the continuous current mains is adapted to connect this main, :j through a resistance m to m the end of one of the three windings, and a switch g connected to the other continuous current maid is adapted to connect the latter either to the end of another of the three windin s,

or to w the neutral point, as may be esired. This arrangement of the winding 0t R2 enables me to start up the machine B after the manner of an induct-ion motor, the switches p and q being open and the contact bars'o and,0 of the resistance R0 being moved in the usual manner to gradually cut out the resistances a 3 2 when a speed approximately that of synchronisin is reached the switches p and q are closed and R1 becomes excited by the continuous current either on one leg or two legs of the three phase winding, and the machinethen runs as a synchronous machine, the wmdmg or windings not connected to the continuous current mains acting as an amortiseur.

Fig. 4 shows clearly the arrangement of the windings of M and N;'Figs. 5 and 6 show the starting up and runnlng connections, respectively, of R2" when the continuous current is .on two legs of the three phase the details described by way of -example,as the -invention is applicable generall and may be considerably modified within the limits of, my invention as claimed herein.v Itis to be understood alsdthat while I have referred to the case as-heing rotated, when. the main motor load is light, in/the same direction as therotor' so as to. accelerate the 'latterto' an absolute speed exceeding that of synchronism, this need notnepessarily be done: The case forinstancernay be held stationary when the main, motor is lightly loaded and bereversely rotated at heavy loads to givethe'generator action. Obviously the rotor smaK,-}. instead of being connecte'd to the ,fly w eel be made sufficiently heavy to form a flywheel itself.

The accompanyingdrawinfiillustrate the arrarigeme'nts diagrammatic y and 'no atthe switch no, limit myself to these applications, nor to 7 ings of the case tempt has been made to illustrate the details of constructions which will be readily understood by those familiar with the art.

In the drawings I have shown the windconnected to the mains and the windings of the rotor connected to the controlling means. It is obvious, however, thatthe rotor windings may be'connected to the mains and the case winding connected to the controlling means. In the statement of claims herein, I have, for the sake of brevity, used the terms rotor and case and I wishit to be understood that I em loyfthese terms to designate the two parts oi an alternatin current machine between which there is re ative movement, and quite irrespecwhic may be iary machine which is mains by both a poly-phase winding for the I declare that l single phase or polytivelof the type of electrical winding employed. For example the alternating current mains to which the one .part ofthe machine is connected may be base. and the winding of the other part 0 the machine may be any convenient arrangement of poly-phase winding. In some cases where the one art of the machine is connected to three-phase mains the other part. of the machine may be wound with' a two-phase winding so that it may be started up as an induction-motor and run as asynchronous motor with the said two-phaseywinding connected to continuous current mains. In some cases also it may auxilnot connected to the purpose of starting upand a continuous current winding for running as a synchronous machine.

Having now fully. described my invention,

whatI claim is:'- 1.. In combination alternating current mains, an alternating current machine other; substantially as 5o chine the rotor of which'is the rotor of which is mechanically connected to a rotating mass and the rotatable. case of which is electrically connected to the mains, and means for continuously rotating the case at various speeds in one direction or the described."

2. In combination with alternating ourrent mains and a motor electrically con: nected thereto, an alternating current mamechanically con-. nected to a rotating mass and therotatable case of which is electrically connected to the mains, and means for continuously rotating the easeat various speeds inone direction or the other; substantially as described.

3. In combination with alternating current mains, an alternating-current machine the rotor of which is mechanically connected to a rotating mass and the rotatable case of which is electrically connected to the mains and an electric motor adapted to rotate the case; substantially as described.

.chine the rotor 4. In combination with alternating cur-l rent mains and a motor electrically connected'thereto, an alternating current maof which is mechanically connected to a rotating mass and'the rotatable case of which is electrically connected to the mains and an electric motor adapted to rotate the case; substantially as described.

5. In combination with three-phase alternating current mains, a three-phase alternating current machine the rotor of which is mechanicall and the rotatable case of which is electrically connected to the mains'and means for continuously rotating the case at various speeds in one direction or the other; substantially as described.

6. In combination with three-phase alternating current mains, a three-phase alterconnected to a rotating mass nating current motor electrically connected thereto, a three-phase alternatlng current machine the rotor of which is mechanically connected to a rotating mass and the rotatable case of which is to the mains, tating the case at various speeds in one direction or the other; substantially as described.

7. In combination with three-phase alternating current mains, a three-phase alter nating current machine the rotor of which is mechanicall connected to a rotating mass and the rotatable case of which is electrically connected to the mains and an electro motor adapted to rotate the case; substantially as described.

8. In combination with three-phase alternating current mains and a three-phase alternating current motor electrically connected thereto, a three phase alternatlng current machine the rotor ofrwhich is mechanically connected to a rotating mas and the rota table case of which is electrically connected electrically connected -to .themains and an electro motor ada ted to rotate the case substantially as descri ed.

9. In combination with alternating cur an alternating, current machine rent malns, the rotor of which is mechanically connected to a rotating mass and the rotatable case of and means for continuously rowhich is electrically connected to the mains,

and a continuous current motor adapted to rotate the case; substantially as described.

10. In'combination with alternating current mains' and a motor nected thereto, an alternating current machine the rotor of which is mechanically. connected to a rotating mass and the rotatable case of which is electrically connected to the mains and a continuous current motor adapted to rotate t e case; substantially as described.

11. In combination with three-phasealternating current mains, a three phase alternating current machine the rotor of which is mechanically connected to a rotatin' mass and the-rotatable case of which'is e ectricelectrically conally connected to'the mains and a continuous-current electromotor adapted to rotate I described.

13. In combination with alternating currentmains, an alternating current machine the rotor of which is mechanically connected to a rotating mass and the rotatable case of which is electrically connected to the mains,

5 continuous current mains, rotor resistances,

switches adapted to connect the rotor winding' either to the resistances or to the direct current mains and means for rotating the case; substantially asdescribed.

14. In combination with alternating current mains, a synchronous alternatin current machine the rotor of which is mec anic ally connected to a rotating mass and the rotatable case of which is electrically connected to the mains, means for starting up the machine as an induction motor and means for rotating the case; substantially as described.

15. In combination with alternating current mains, a synchronous alternatin current machine the rotor of which is mec anically connected to a rotating mass, and the rotatable case of which is electrically connected to the mains, means for starting up the machine asan induction motor, and a continuous current motor adapted to rotate the case; substantially as described.

16. In combination with alternating current mains, a synchronous alternatin current machine the rotor of which is mechanically connected to a rotating mass'and the rotatable case of which is electrically con nected to the mains, means for starting up the machine as an induction motor, a continuous current motor adapted to rotate the case, and means for varying and reversing the armature current of the said continuous current motor; substantially as described.

17. In combination with alternating current mains, a synchronous alternating ourrent machine comprising. a rotor and a rotatable case, said rotor being mechanically connected to a rotating mass and the rotatable case'being electrically connected to-the mains, means for starting up'the machine as an induction motor, a cont nuous current motor adapted to rotate the case, continuous current mains, a second contmuous current machine driven by the alternating current machine the armature of which latter iscon nected to thdarmature of the continuous current motor and the field of which is connected to the continuous current mains, a rheostat and a reversing switch to control the fiel d of the second continuous current machine; substantially as described.

18. In combination the mains supplied with alternating current, the mains supplied with continuous current, the alternating machine, rotor resistances, the fly wheel, the continuous current motor, the, means for varying the direction of rotation and the speed of the continuous current motor and Jhe means for connecting the alternating current machine rotor to the resistances to start up and to the continuous current mains to run as a synchronousmachine; substantially as described.

19. In combinat on, the mains supplied with alternatingcurrent', the mains supplied with continuous current, the alternating machine comprising a rotor and a rotatable case, rotor resistances, the fly wheel, the continuous current generator driven by the alternating'machine the motor to drive the case the armature of which motor is connected in series with the armature of the continuous current machine, the rheostatthe reversing switch to control the field of the continuous current generator, and the switch gear to connect the alternating current macontinuous current mains; substantially as described.

20. In combination the alternating current mains, an alternating current machine connected to the alternatlng current mains the rotor of which is connected to a heavy rotating mass and the case of which is adapted to rotate, and means for continuously rotating the case at various speeds in one direction or the other; substantially as described.

21. In combination the a1ternating'current mains, an alternating current machine connected thereto the rotor of which is connected to a heavy rotatin mass and the case of which is adapted to e rotated, and an electro motor to rotate the said case; substantially as described.

22. In combination the alternating current mains, an alternating current machine connected thereto the rotor of which is connected to a heavy rotating mass and the'case of which is adapted to be rotated, continuous current mains and a continuous current motor adapted to rotate the said case; substantially as described.

23. In combination, the alternating current mains, the alternatingcurrent machine connected thereto and adapted to be startedup as an induction motorand to run as a synchronous machin the rotor of which is connected to a heavy rotating mass and the I case of which is adapted to rotate, continuchine rotor either to the resistances or to the V erator excited by the continuous current malns, a contlnuous current motor ada ted to drive the case and the armature of w ich citation 0 the continuous current generator ;v

substantially as described.

In witness whereof I have hereunto set my hand in the presence of two subscribing 10 witnesses. I

ROBERT STAFFORD MGLEOD.

Witnesses:

J. E. LLOYD BARNES, H. THOMAS, 

